One-component polyurethane, which has been widely used for the purpose of insulation, soundproofing, filling, sealing, etc. in various fields as well as a building, is provided as it is together with high-pressure gas filled in a pressurized container.
FIG. 1 schematically shows a conventional disposable dispensing gun for dispensing polyurethane. As shown therein, the conventional disposable dispensing gun includes an adaptor main body 10 put on and coupled to a valve stem VS formed at a top center portion of a pressurized container PC, a protruding lever 20 stationed in a direction transverse to the adaptor main body 10, a discharging portion 30 having a predetermined angle to an end portion of the adaptor main body 10, and an injection pipe 32 coupled to the discharging portion 30.
To use such a dispensing gun, a user generally needs both hands. For example, a user holds the pressurized container PC upside down with one hand, and obliquely upward pulls the lever for operation 20 protruded from the adaptor main body 10 with the other hand. The operation of the lever 20 makes a lower end portion of the valve stem VS be inclined to open a valve, so that one-component polyurethane liquid filled in the pressurized container PC can come out to the adaptor through the valve stem VS. The liquid polyurethane coming out to the outside is discharged to a target place via a hollow pipe formed in the adaptor main body 10, a discharging pipe 30 and an outlet pipe 32.
However, such a conventional disposable dispensing gun is difficult to be held with one hand since the lever for operation 20 is disposed distantly from the main body of the pressurized container PC, and thus both hands are needed. If both hands are not free during dispensing works for a building or the like equipment, there are problems of significantly lowering work efficiency and safety.
Further, if the work is temporarily suspended in the state that polyurethane remains inside the pressurized container, the residual polyurethane in the outlet pipe 32, the discharging pipe 30 or the like becomes hard, and therefore the dispensing adaptor has to be chucked away and replaced by a new one in order to the work.